The UTG Pro Receiver Extension Tube is a 6-position Mil-spec diameter buffer tube designed for AR-15 rifles featuring a durable Flat Dark Earth (FDE) finish and precision engineering.UTG Pro 6-Position Receiver Extension TubeCNC Machined from 6061-T6 Aircraft Grade AluminumPrecisely rolled threads for durable engagement with lower receiverTightest tolerance control for zero-gap fitFlat Dark Earth (FDE) finishFits any standard AR-15 lower receiverCompatible with Mil-Spec diameter collapsible stocksEssential for AR-15 builds and upgrades this receiver extension tube provides reliable stock attachment and buffer system housing with professional-grade durability and precision fit.